Realtors are slowly growing more confident about the sales of single-family homes, townhouses and condominiums, according to a December survey of more than 3,000 real estate agents by the National Association of Realtors. NAR's December confidence index for current single-family home sales jumped 29% to 31.6 from 24.5 a year earlier. November's score was 30.4. For townhouses, the confidence index in December rose 47% to 18.5 from 12.6 a year earlier, while confidence about condominiums rose 39% to 14.3 from 10.3 a year earlier. Both areas had monthly declines, however. The index measures Realtors' attitudes toward the strength of the current housing market and expectations about the future. The questions are designed to capture effects of existing economic conditions and trends on the real estate business. A response of “strong” receives 100 points, while “moderate” receives 50 points and “weak” is assigned 0 points. The index provides the average score for each question. Realtors' expected outlook is gaining confidence as well. The index for all three sectors remains under 50, but still increased in December from a year earlier. Write to Justin T. Hilley. Follow him on Twitter @JustinHilley.